Since the ‘90s, Venus and Serena Williams have kept audiences in awe, inspiring athletes of all ages. In fact, Serena just won her sixth Wimbledon title. And, despite dealing with negativity and haters (like last week’s wave of body-shaming aimed at Serena), the sisters always keep their cool and their commitment—to tennis, to kicking butt, and each other—continuing to make history. (Venus was even named one of The 6 Best Bodies from ESPN The Magazine's Body Issue in 2014.)

So when Jamba Juice and ClassPass offered us the chance to do a boxing workout with Venus Williams to celebrate the juice company’s new freshly squeezed juices, we jumped at the chance. Afterwards, we sat down with Williams to talk workout fuel, family, and her fun new hobby (dancing!).

Shape: You say you’ve gotten into dance classes. Are there other workouts you like to do when you need a break from tennis?Venus Williams (VW): The dancing is really for fun. I have gotten flexible, that’s the key factor. But my workouts are really focused, whether it’s in the gym or on the bike or Pilates—whatever it is, it’s all to get stronger and better.

Shape: We’re at a boxing gym now…what about that? Have you ever boxed before or was the class today new for you?VW: Not at all! Serena has done some boxing over the years…I never joined in. So I can tell her I’m a boxer now!

Shape: Let’s talk about food. What are some of your favorite meals or snacks to fuel your workouts?VW: I don’t snack a lot, because I didn’t grow up snacking. Sometimes I will but mostly I don’t. I do love juices and smoothies though because it’s an easy way to refuel quickly. And if I want more protein after working out, I can always get that balance. A lot of times I don’t just do juice, I do the whole thing blended to keep the fiber.

Shape: You’ve talked before about being a vegan. Do you think that it’s helped you with your immune system? [Williams has Sjogren’s syndrome, an autoimmune disease, and follows a mostly vegan, or what she has called a “cheagan” (cheating vegan), diet to help with her symptoms.]VW: I do think so. I think it’s a great lifestyle for long-term stability. You also have to look at everything else in your regimen, what you’re putting into your body, like supplements. I’m always learning and I’m hoping to perfect my system.

Shape: Switching gears. You’ve been a huge activist for women in sports. [Williams was instrumental in fighting for equal prize money for male and female tennis players.] What do you think is the next challenge for female athletes?VW: I think women athletes who have been successful need to help other sports, those sports that are just emerging. That’s what I’ve been thinking about and looking forward do. Tennis has been around for so long—women have been playing the majors since the 1800s. Other sports have not had professional leagues for women for as long.

Shape: What are some of the other sports you take an interest in?VW: Basketball, soccer, some of those. They’re growing and they’re getting there, but they haven’t had the head start that tennis has had.

Shape: Millions of young girls look up to you as a role model. Who are some of your role models?VW: My parents and my sisters. We all just encourage each other so much. When one person was doing well it really motivated all of us.

Shape: How has that family support and environment helped you?VW: It’s just been amazing, how much we’ve been able to support each other. It’s not just Serena and I—we’ve been able to all pull together. Sometimes in families, it can tear people apart when one person is more successful…it hasn’t been like that in our family at all, no matter who won or lost or who was in the spotlight or not. I’m grateful for that.